Welcome to HVAC-Talk.com, a non-DIY site and the ultimate Source for HVAC Information & Knowledge Sharing for the industry professional! Here you can join over 150,000 HVAC Professionals & enthusiasts from around the world discussing all things related to HVAC/R. You are currently viewing as a NON-REGISTERED guest which gives you limited access to view discussions

To gain full access to our forums you must register; for a free account. As a registered Guest you will be able to:

Participate in over 40 different forums and search/browse from nearly 3 million posts.

trippint0, when i started the sytem up it was running in a vacuum..i added a couple oz to get it to 10 psi the head psi was a little less than 100 at that time.
im going back saturday to pump it up to look for the leak as you suggested..ive done this once before, so i pulled a vacuum and recharged it so i knew what was in it..4 days later its running in a vacuum just like the 1st time i seen it..

this box is built into the building..........the condensor is in a bar and clean. the box is in good condition..
if the cap tube was plugged why did the system come down in a hour or less??

Glad to hear that the box is in decent condition. Well, obviously if it pulled down to temp, then the cap tube isn't totally restricted. It's just that in my experience, for R134a, 8# suction is low. Usually I see 17-20# when box is hot and 12# when box is closer to temp. And 180# head sounds a little high. As far as pull down time, it depends on if the box is empty or loaded with product, and it depends on the size of the box in relation to the refrigeration system. On an empty box, 1 hour is a really long pull down time (unless it is a pretty big box...)

83*f return gas sounds warm - even if cap tube is strapped to suction line, usually I'll still at least see the suction line cold and sweating. And yes, having the condensing unit out of the hole will raise head pressure, since Bev-Air typically doesn't use fan shrouds on most models I've seen.

One way to check for restrictions, is to pull a vacuum, weigh in the charge so you know the charge is correct. Bleed high side liquid back in, etc. Then after a while, just pull the evaporator cover and look at the coil. If all the U-Bends are evenly frosted up, that is a great sign. However, if you have frost at the cap tube entrance or just the first couple rows of the evaporator and the rest is dry, you probably have a restriction. With an 8# suction pressure, I would expect to find either - 1) low on charge, 2) restriction. The only other cause I know of for low suction would be frozen evaporator, or evap fan blades on backwards, however with such high superheat at the compressor, this diagnosis is effectively ruled out.

Good luck!

*edit* I just read that you already weighed in the charge. Sorry I missed that before I replied.

* another edit * I will also add that I don't have a lot of experience with Bev-Air, so not really exactly sure what suction pressure should be with box at 34*f. Still with such a hot suction line, something seems "out of balance."

Yeah sounds restricted!! Usually i find the liquid line at room temp when its restricted and still running on factory charge. Yours is most likely overcharged. Pull the charge and weigh back in. Or just go ahead and change the cap tube. Also the POS may afterall have a leak too!!!

If you can't pick up the 134, 22 and nitrogen should solve the problem. Paint coming off the u tubes on the evap? Does this unit have an accumulator attached to the evap? Sounds like a good sized leak if it needs recharging every 5 days. Double check the high side.

Officially, Down for the count

YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET

I know enough to know, I don't know enoughLiberalism-Ideas so good they mandate them

Pull the insulation off the suction line loop. Cap tube maybe leaking where its soldered to the suction line! Had one last week on a perlick! Took me a minute to find it. Only because i ran across the same sitiuation before that took me hours to find and lots of frustration.

has anyone had any success with the leak sealers you blow into a system?

I would only do this as an absolute LAST resort. And after describing to the customer how much it can screw up the system.
In fact, I actually wouldn't do this at all. Unless the customer insisted and I had a can left on the truck I was trying to use up.

You need to determine if this thing has a leak or is just restricted. You have a good leak detector, so a shot of 22 and 150# of nitrogen you should be able to find the leak.

As mentioned, most likely evap accumulator or evap tubing where the fins are crimped around.